Seal structure of mold for manufacturing composite material structure

ABSTRACT

A seal structure is used in a mold constituted by a plurality of segments to manufacture a hollow composite material structure. In the seal structure, a seal member formed in a line shape having ends is inserted in a seal groove provided on at least one of adjacent side surfaces of the segments. A lip portion is provided at a seal upper portion of the seal member such that at least a tip end of the lip portion projects to an outside of the seal groove. When the adjacent side surfaces of the segments are coupled to each other, the seal member is crushed in a cross sectional direction by the other of the adjacent side surfaces of the segments. With this, complication of the manufacture of the composite material structure can be suppressed or avoided while realizing a satisfactory sealed state between the adjacent segments.

TECHNICAL FIELD

The present invention relates to a seal structure of a mold formanufacturing a hollow composite material structure, the mold beinglocated inside the composite material structure, being constituted by aplurality of segments, and being kept as a single structure by couplingadjacent side surfaces of the segments to each other, the seal structurebeing provided at the adjacent side surfaces of the segments. Thepresent invention particularly relates to a seal structure of a moldused for manufacturing a composite material structure for use as afuselage of an aircraft.

BACKGROUND ART

In recent years, fiber-reinforced resin composite materials (hereinaftersuitably abbreviated as “composite materials”) are widely used in thefields in which metal materials have been conventionally used. Among thecomposite materials, carbon fiber reinforced materials formed byimpregnating carbon fibers as reinforced fibers with matrix resin suchas epoxy resin are lighter and stronger than the metal materials.Therefore, the carbon fiber reinforced materials are widely adopted inthe fields of sports goods, industrial machines, aerospace, and thelike.

In the field of aerospace among these fields, for example, stiffenedpanels formed by integrating skins and stiffeners made of the compositematerial are adopted in structures, such as wings and fuselages ofaircrafts. One of typical stiffeners is a stringer. Examples of themethod of integrating the stiffeners made of the composite material andthe skins made of the composite material include a co-curing method anda co-bonding method. According to the co-curing method, a plurality ofprepregs which become the stiffeners are laminated, and a plurality ofprepregs which become the skins are laminated. Then, these prepregs arecured by an autoclave to be integrally molded. According to theco-bonding method, after the stiffeners are first cured by theautoclave, a plurality of prepregs which become the skins are laminatedand cured by the autoclave to be integrally molded.

One example of the technology for manufacturing such structures of theaircrafts is a composite tool for molding a cylinder-shaped portion asdisclosed in PTL 1. In order to manufacture the cylinder-shaped portionmade of the composite material, the composite tool is configured by:arranging a plurality of (seven, for example) members or tiles in acylindrical manner; and coupling the members or tiles to one another.Seal units (seal members) are arranged at respective coupled portionseach between the members (tiles).

A specific example of the seal unit is an O-ring gasket that isexpandable. Grooves in which the O-ring gaskets are provided are locatedon respective side surfaces of the adjacent members (tiles) so as to bedisplaced from each other (so as to be alternately arranged), and theO-ring gaskets are arranged in these grooves. The O-ring gasket has ahollow structure (tubular structure) in a section thereof and isexpandable by a pressure difference generated during autoclaving.

The O-ring gasket seals between the adjacent members in a longitudinaldirection. Therefore, in PTL 1, in order to realize sealing at endportions of the adjacent members, a leak prevention insertion portion isprovided at the end portions. The insertion portion includes two holesfacing the groove at which the O-ring gasket is arranged. A part of theO-ring gasket is exposed to an outside through between the adjacentmembers. The exposed O-ring gasket is connected to a high-pressure airsource. With this, the O-ring gasket can be expanded by pressurizing aninside of the O-ring gasket.

According to PTL 1, in order not to weaken the structures of the members(tiles), the grooves are formed on the adjacent side surfaces of themembers so as to be provided alternately (so as to be displaced fromeach other). Further, since the O-ring gaskets are provided at thegrooves arranged as above, the O-ring gaskets are also provided so as tobe displaced from each other. Therefore, by the pressurization of theinside of the O-ring gasket by the high-pressure air source in additionto the pressure difference generated by the autoclave, the O-ring gasketarranged at one of the adjacent side surfaces of the members expands tocontact the other side surface, and the O-ring gasket arranged at theother side surface expands to contact the one side surface. With this,double seal is realized between the adjacent members.

CITATION LIST Patent Literature

PTL 1: Published Japanese Translation of PCT Application No. 2010-507504

SUMMARY OF INVENTION Technical Problem

However, according to the configuration disclosed in PTL 1, in order torealize a stable sealed state, various conditions need to beappropriately adjusted as below. Therefore, the method of manufacturingthe cylinder-shaped portion may become complex.

For example, the O-ring gasket disclosed in PTL 1 is a seal unit (sealmember) that is intended to expand. Therefore, in order to realize asatisfactory and stable sealed state, conditions of the autoclave needto be set to generate a preferred pressure difference, and shop air ofadequate pressure needs to be continuously supplied from an outsideduring the autoclaving.

Further, heat expansion of the O-ring gasket during the autoclavingneeds to be considered. For example, in order to realize a predeterminedexpansion coefficient in a cross sectional direction of the tubularstructure, a thermal expansion coefficient in the cross sectionaldirection needs to be considered in addition to the pressure differenceof the autoclave and the pressure of the shop air. Further, as describedabove, since the O-ring gasket is partially exposed from both endportions of the coupled portion, the amount of exposure is predicted toincrease by heat expansion in a line direction. Therefore, the O-ringgasket needs to be fixed at the leak prevention insertion portion suchthat the increase in the amount of exposure due to the heat expansion isprevented while keeping the hollow state of the tubular structure.

Instead of the seal member configured to expand by the pressuredifference as disclosed in PTL 1, a seal member configured to becompressed (crushed) in the cross sectional direction by a load may beused. However, according to the seal member configured to be compressed,as a seal length of the segment (the member or the tile in PTL 1)constituting the mold (the composite tool in PTL 1) increases, the loadfor compressing the seal member increases. The load may further increasedepending on the hardness and shape of the seal member.

Therefore, when one segment is moved to be combined with the othersegment, the segment needs to be moved by a large load for compressingthe seal member. In order to manufacture high-quality composite materialstructures, it is preferable that a level difference be little betweenouter peripheral surfaces of the adjacent segments. However, as the loadduring the movement of the segment increases, the degree of difficultyof position adjustment of the segments increases. Therefore, assemblywork of the mold becomes complex.

The present invention was made to solve the above problems, and anobject of the present invention is to provide a seal structure of a moldused for manufacturing a hollow composite material structure andconstituted by a plurality of segments, the seal structure being capableof suppressing or avoiding complication of the manufacture of thecomposite material structure while realizing a satisfactory sealed statebetween the adjacent segments.

Solution to Problem

To solve the above problems, a seal structure of a mold formanufacturing a composite material structure according to the presentinvention is a seal structure of a mold for manufacturing a hollowcomposite material structure, the mold being located in the hollowcomposite material structure, being constituted by a plurality ofsegments, and being kept as a single structure by coupling adjacent sidesurfaces of the segments to each other, the seal structure beingprovided at the adjacent side surfaces of the segments. The sealstructure includes: seal grooves each provided on at least one of theadjacent side surfaces of the segments; and seal members each formed ina line shape having ends and inserted in the seal groove to seal betweenthe segments by coupling the adjacent side surfaces of the segments toeach other. A part of the seal member which part contacts a bottomsurface of the seal groove when the seal member is inserted in the sealgroove is referred to as a seal bottom portion. A part of the sealmember which part is opposed to the seal bottom portion is referred toas a seal upper portion. A lip portion is provided at the seal upperportion such that at least a tip end of the lip portion projects to anoutside of the seal groove when the seal member is inserted in the sealgroove. The seal member is hollow therein or includes a concave portionon at least the seal bottom portion of the seal member. When theadjacent side surfaces of the segments are coupled to each other, theseal member is crushed in a cross sectional direction by the other ofthe adjacent side surfaces of the segments.

According to the above configuration, the seal member includes the lipportion and the hollow or concave portion and is formed in a lineconfiguration having ends. Therefore, regarding the cross sectionaldirection of the seal member, the sealed state can be formed bycompressing the seal member without applying a high load. Regarding alongitudinal direction of the seal member, the expansion (linearexpansion) in the longitudinal direction generated by the heating duringthe autoclaving can be easily adjusted by both end portions of the sealmember. With this, the more satisfactory and stable sealed state can berealized between the adjacent segments. In addition, since the increasein the moving load of the segment can be suppressed or avoided, thelevel difference between the adjacent segments can be satisfactorilyadjusted when assembling the mold. As a result, the complication of themanufacture of the composite material structure can be suppressed oravoided while realizing the satisfactory sealed state between theadjacent segments.

Advantageous Effects of Invention

According to the above configuration, the present invention has aneffect of being able to provide a seal structure of a mold used formanufacturing a hollow composite material structure and constituted by aplurality of segments, the seal structure being capable of suppressingor avoiding complication of manufacture of the composite materialstructure while realizing a satisfactory sealed state between theadjacent segments.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1A is a schematic perspective view showing one example of theconfiguration of a mold for manufacturing a composite material structureaccording to the present embodiment. FIG. 1B is a schematic end surfaceview showing one example of the configuration of a mandrel included inthe mold for manufacturing the composite material structure shown inFIG. 1A.

FIG. 2A is a perspective view showing the configuration of a firstsegment forming a cylindrical structure of the mold for manufacturingthe composite material structure shown in FIGS. 1A and 1B. FIG. 2B is asurface view showing an end portion of the first segment shown in FIG.2A.

FIG. 3A is a perspective view showing the configuration of a secondsegment forming the cylindrical structure of the mold for manufacturingthe composite material structure shown in FIGS. 1A and 1B. FIG. 3B is asurface view showing an end portion of the second segment shown in FIG.3A.

FIG. 4 is a schematic perspective view showing one example of assemblingof the mold for manufacturing the composite material structure shown inFIG. 1A.

FIGS. 5A to 5C are partial sectional views each showing one end portionof the first segment of the mold for manufacturing the compositematerial structure shown in FIG. 1A and schematically show a part of aprocess of manufacturing the cylindrical composite material structure byusing the mold.

FIGS. 6A and 6B are partial sectional views each showing the mold formanufacturing the composite material structure shown in FIG. 1A and showone example of a seal structure according to the present embodiment, theseal structure being applied to the mold.

FIGS. 7A to 7F are cross sectional views showing typical examples of aseal member included in the seal structure shown in FIG. 6A or 6B.

FIG. 8A is a partial perspective view of the first segment and showsthat a seal end portion pressing member included in the seal structureshown in FIG. 6A or 6B is not attached yet. FIG. 8B is a partialperspective view of the first segment and shows that the seal endportion pressing member is attached to the first segment shown in FIG.8A.

FIGS. 9A to 9D are schematic process diagrams showing a process ofconstructing the seal structure shown in FIG. 6B.

DESCRIPTION OF EMBODIMENTS

Hereinafter, a representative embodiment of the present invention willbe explained with reference to the drawings. In the followingexplanations and the drawings, the same reference signs are used for thesame or corresponding components, and a repetition of the sameexplanation is avoided.

Mold for Manufacturing Composite Material Structure

First, a mold for manufacturing a composite material structure(hereinafter referred to as a “mold”) according to the presentembodiment will be explained with reference to FIGS. 1A to 4.

As shown in FIG. 1A, a mold 10 according to the present embodimentincludes at least a mandrel 11 and a pair of support rings 12. Themandrel 11 is a single cylindrical structure (cylindrical member), andthe support rings 12 are located at both ends of the mandrel 11. Themandrel 11 is formed by coupling side surfaces of six segments, i.e.,three first segments 20 and three second segments 30 to one another. Asschematically shown in FIG. 1B, in the mandrel 11, the first segments 20and the second segments 30 are alternately coupled to one another. Bothends of the mandrel 11 are supported by the respective support rings 12.Thus, the six segments 20 and 30 are kept in a cylindrical shape.

As shown in FIG. 1A, a plurality of vacuum suction holes 13 are providedon surfaces of both end portions of the segments 20 and 30. Each of endportions of a seal groove 25 is exposed between a peripheral edgesurface of an end portion of the segment 20 and a peripheral edgesurface of an end portion of the adjacent segment 30. A below-describedseal member is inserted into the seal groove 25. In FIG. 1B, parts Pssurrounded by dotted lines are positions at which seal structures of themold 10 are provided. The parts Ps correspond to positions at each ofwhich the side surface of the first segment 20 and the side surface ofthe second segment 30 are coupled to each other. The seal structureaccording to the present embodiment includes the seal groove 25 shown inFIG. 1A. The seal structure will be described later.

Groove-shaped concave portions to which stringers are attached areformed on an outer peripheral surface of the mandrel 11 except forperipheral edges of both end portions of the mandrel 11. In order toclearly show the configurations of the mandrel 11 and the segments 20and 30, the groove-shaped concave portions are not shown in FIG. 1A andthe other drawings showing the mandrel 11 and the segments 20 and 30.

As shown in FIG. 2A, the first segment 20 is formed in a rectangularflat plate shape. A surface of the first segment 20 which surfaceconstitutes the outer peripheral surface of the mandrel 11 is referredto as a “segment front surface 21,” and the segment front surface 21 isa convex curved surface (a convex surface or a projectingly curvedsurface). Further, the peripheral edge surfaces of both end portions ofthe first segment 20 are referred to as “segment end portion surfaces22,” and the vacuum suction holes 13 are provided on the segment endportion surfaces 22.

A surface of the first segment 20 which surface is coupled to theadjacent second segment 30 is referred to as a “segment side surface23.” As shown in FIGS. 2A and 2B, when the first segment 20 ishorizontally arranged with the segment front surface 21 facing upward,the seal grooves 25 are provided on the segment side surfaces 23 in alongitudinal direction of the segment side surface 23. In the presentembodiment, as shown in FIG. 2A, both end portions of the seal groove 25are bent toward the respective segment end portion surfaces 22.

A surface of the first segment 20 which surface constitutes an endsurface of the mandrel 11 is referred to as a “segment end surface 24.”As shown in FIGS. 2A and 2B, the seal groove 25 cannot be visuallyconfirmed from the segment end surface 24. Therefore, in FIG. 2B, theseal grooves 25 are shown by broken lines. In order to couple thesegment side surface 23 of the first segment 20 to the side surface ofthe second segment 30, a coupling member (not shown) is provided on thesegment side surface 23 of the first segment 20. In order to fix thesegment end surface 24 to the support ring 12, a fixing member (notshown) is provided on the segment end surface 24.

Each of both segment side surfaces 23 of the first segment 20 faces ahorizontal direction or a direction inclined upward relative to thehorizontal direction. In the present embodiment, as shown in FIG. 2B,for example, a normal direction of the segment side surface 23 extendsin the direction inclined upward relative to the horizontal direction.

As described below, in the present embodiment, when assembling themandrel 11 in a cylindrical shape, the second segments 30 are firstfixed to the support rings 12, and each of the first segments 20 is thenfitted between the second segments 30 from a lower side to an upper sideto be fixed. Therefore, in order not to hinder this fitting work, thesegment side surface 23 of the first segment 20 is only required to beformed such that the normal direction of the segment side surface 23extends (is directed) in the horizontal direction (direction shown by anarrow Ar1 in FIG. 2B). In other words, when the first segment 20 isarranged horizontally, the segment side surface 23 is located along avertical direction (direction along a one-dot chain line shown in FIG.2B).

After the cylindrical composite material structure (for example, aone-piece barrel (OPB)) is molded by using the mold 10 including themandrel 11, the composite material structure is removed from the mold10. This removal is performed by disassembling the mandrel 11. Thedisassembling of the mandrel 11 is performed in the reverse order to theassembling of the mandrel 11. Therefore, each of the first segments 20is pulled out from between the second segments 30.

On this account, as shown in FIG. 2B, it is preferable that the segmentside surface 23 of the first segment 20 be formed such that the normaldirection of the segment side surface 23 is inclined upward (toward thesegment front surface 21, i.e., in a direction shown by an arrow Ar2 inFIG. 2B). The upward inclination of the normal direction of the segmentside surface 23 denotes that the segment side surface 23 is inclined soas to face upward. In other words, the segment side surface 23 isinclined such that a rear-side edge of the segment side surface 23spreads more outward than a front-side edge of the segment side surface23. The inclination of the segment side surface 23 form “draft” on thesegment side surface 23 of the first segment 20. Thus, the first segment20 is easily pulled out from between the second segments 30, andtherefore, the mandrel 11 is easily disassembled.

The inclination angle (draft angle) of the segment side surface 23 isnot especially limited and is suitably set to a preferred angledepending on specific shapes, dimensions, and the like of the mandrel 11and the mold 10. For example, in the present embodiment, the inclinationangle (draft angle) of the segment side surface 23 may be set to 8 to 12degrees, preferably about 10 degrees. The inclination angles of theopposing segment side surfaces 23 may be equal to each other ordifferent from each other.

As shown in FIG. 3A, as with the first segment 20, the second segment 30is formed in a rectangular flat plate shape. A surface of the secondsegment 30 which surface constitutes the outer peripheral surface of themandrel 11 is referred to as a “segment front surface 31,” and thesegment front surface 31 is a convex curved surface as with the segmentfront surface 21 of the first segment 20. Further, as with the firstsegment 20, the peripheral edge surfaces of both end portions of thesecond segment 30 are referred to as “segment end portion surfaces 32,”and the vacuum suction holes 13 are provided on the segment end portionsurfaces 32.

A surface of the second segment 30 which surface is coupled to theadjacent first segment 20 is referred to as a “segment side surface 33.”Each of both segment side surfaces 33 has a shape that faces a directioninclined downward relative to the horizontal direction. To be specific,both segment side surfaces 33 are inclined such that the width of thesecond segment 30 increases from a rear side of the second segment 30toward the segment front surface 31.

As described below, in the present embodiment, when assembling themandrel 11 in a cylindrical shape, the second segments 30 are firstfixed to the support rings 12, and each of the first segments 20 is thenfitted between the second segments 30. Therefore, in order not to hinderthe fitting work of the first segment 20, it is preferable that the areaof the rear side of the second segment 30 fixed first be small. On thisaccount, it is preferable that each of both segment side surfaces 33 ofthe second segment 30 be formed such that the normal direction of thesegment side surface 33 extends downward (direction shown by an arrowAr3 in FIG. 3B), in other words, the segment side surface 33 is inclineddownward.

In order to couple the segment side surface 33 to the segment sidesurface 23 of the first segment 20, a coupling member (not shown) isprovided on the segment side surface 33. A surface of the second segment30 which surface constitutes the end surface of the mandrel 11 isreferred to as a “segment end surface 34.” In order to fix the segmentend surface 34 to the support ring 12, a fixing member (not shown) isprovided on the segment end surface 34 as with the segment end surface24 of the first segment 20.

An eave portion 35 projecting outward from the segment side surface 33is provided at an edge portion of the segment side surface 33 of thesecond segment 30, the edge portion being connected to the segment frontsurface 31. Therefore, as shown in FIGS. 3A and 3B, when the secondsegment 30 is viewed from the segment front surface 31, the segment sidesurfaces 33 facing downward are completely hidden by the eave portions35.

The degree of the downward inclination of the segment side surface 33and the degree of the projection of the eave portion 35 are notespecially limited and are suitably set in accordance with the specificconfiguration of the mandrel 11, the specific configuration of thesecond segment 30, or the specific configuration of the first segment 20coupled to the second segment 30.

As shown in FIG. 3B, an end surface of the eave portion 35 constitutes apart of the segment side surface 33. Therefore, the segment side surface33 of the second segment 30 is constituted by two surfaces that are amain body side surface of the second segment 30 and the end surface ofthe eave portion 35 projecting from the main body side surface. However,the specific configuration of the segment side surface 33 is notespecially limited, and the segment side surface 33 may be constitutedby a single surface without a level difference or may be constituted bythree or more surfaces.

In the present embodiment, the end surface of the eave portion 35 in thesegment side surface 33 is coupled to a part of the segment side surface23 of the first segment 20 (see the parts Ps in FIG. 1B). Thebelow-described seal structure is provided on the part of the segmentside surface 23 to which part the end surface of the eave portion 35 iscoupled. Therefore, the segment side surface 23 of the segment 20 andthe segment side surface 33 of the segment 30 do not have to be entirelycoupled to each other, and as in the present embodiment, a part of thesegment side surface 23 and a part of the segment side surface 33 may becoupled to each other.

Molding of Composite Material Structure

Next, one example of a method of molding (manufacturing) the compositematerial structure by using the above-described mold 10 will bespecifically explained with reference to FIGS. 4 and 5A to 5C.

First, as described above, regarding the mold 10 (see FIG. 1A), the sixsegments 20 and 30 are fixed to the support rings 12 to be assembled asthe mandrel 11 that is a single cylindrical structure.

Before the six segments 20 and 30 are assembled as the mandrel 11, someof parts constituting the composite material structure are attached tothe six segments 20 and 30. For example, as described above, thegroove-shaped concave portions (not shown) are provided on the segmentfront surfaces 21 of the segments 20 and the segment front surfaces 31of the segments 30, and stiffeners, such as stringers, are attached tothe groove-shaped concave portions. After such parts are attached to thesegments 20 and 30, the segments 20 and 30 are assembled to constructthe mandrel 11.

As shown in FIG. 4, the support rings 12 are supported in a standingstate by respective cradles 41 (mandrel support structures) so as to berotatable. Each of the cradles 41 includes a plurality of supportrollers configured to rotate the support ring 12. A pair of supportrings 12 are supported by a pair of cradles 41. A precision rail 42(mandrel assembling/disassembling apparatus) is provided at a positionbetween the support rings 12 and corresponding to the hollow portions ofthe annular support rings 12.

The precision rail 42 is an assembling apparatus by which the sixsegments 20 and 30 are fixed and assembled to the support rings 12. Asshown in FIG. 4, the precision rail 42 includes a jack portion 43, arail main body 44, and the like. One first segment 20 or one secondsegment 30 is placed on an upper side of the jack portion 43, and thejack portion 43 lifts the first segment 20 or the second segment 30 in adirection of 12 o'clock, i.e., upward. The rail main body 44 supportsthe jack portion 43 and the like and includes, for example, a drivemechanism configured to drive the jack portion 43.

As described above, in the present embodiment, when assembling the sixsegments 20 and 30 as the mandrel 11 that is a single structure, first,the three second segments 30 are fixed to the support rings 12.

For example, the first one of the three second segments 30 is placed onthe jack portion 43, and the jack portion 43 lifts the second segment 30in the direction of 12 o'clock (vertically upper direction) such thatthe second segment 30 reaches an upper position of the support rings 12.In this state, the segment end surfaces 34 of the second segment 30 arefixed to respective inner surfaces (fixing surfaces) of the supportrings 12 by the fixing members (not shown).

After that, the support rings 12 are rotated by the cradles 41 by about120 degrees corresponding to two segments. With this, the second segment30 fixed at the upper position in FIG. 4 is moved to a lower position,and therefore, nothing is fixed at the upper position. Then, the secondone and third one of the three second segments 30 are fixed to thesupport rings 12 and rotated in the same manner as the first one of thethree second segments 30. After the third one of the second segments 30is fixed, the support rings 12 are rotated by about 60 degreescorresponding to one segment. With this, the three second segments 30are fixed at every other fixing positions of the support rings 12.

Then, the first one of the three first segments 20 is placed on the jackportion 43, and the jack portion 43 lifts the first segment 20 in thedirection of 12 o'clock (vertically upper direction) such that the firstsegment 20 reaches the upper position of the support rings 12. In thisstate, the first segment 20 is inserted between the two second segments30 fixed in advance. The segment end surfaces 34 of the first segment 20are fixed to the respective inner surfaces (fixing surfaces) of thesupport rings 12, and the segment side surfaces 23 of the first segment20 are coupled to the segment side surfaces 33 of the second segments 30by the coupling members (not shown).

After that, the support rings 12 are rotated by the cradle 41 by about120 degrees corresponding to two segments. With this, the first segment20 fixed at the upper position in FIG. 4 is moved to the lower position,and therefore, nothing is fixed at the upper position. Then, the secondone and third one of the three first segments 20 are fixed to thesupport rings 12 in the same manner as the first one of the three firstsegments 20 and are coupled to the adjacent second segments 30. Withthis, the mandrel 11 that is a single structure is assembled between thesupport rings 12. It should be noted that FIG. 4 shows that the thirdone (last one) of the three first segments 20 is placed on the jackportion 43.

After the mold 10 is constructed as above, a prepreg 50 is laminated onthe outer peripheral surface of the mandrel 11 as shown in FIG. 5A. Themethod of laminating the prepreg 50 is not especially limited.Typically, by an automatic lamination apparatus including a laminationroller, the prepreg 50 is laminated by being attached to the mandrel 11while rotating the mandrel 11.

FIGS. 5A to 5C schematically show a part of a section of an end portionof the first segment 20 constituting the mandrel 11. Basically, thesecond segment 30 has the same configuration as FIGS. 5A to 5C.Therefore, the configuration of the first segment 20 explained withreference to FIGS. 5A to 5C corresponds to the configuration of thesecond segment 30 unless otherwise noted.

As schematically shown in FIGS. 5A to 5C, since the segment frontsurface 21 constitutes the outer peripheral surface of the mandrel 11,the prepreg 50 is laminated on the segment front surface 21. Asdescribed above, the segment end surface 24 of the first segment 20 isfixed by a fixing member 16. Further, as described above, the vacuumsuction holes 13 are provided on the segment end portion surface 22 ofthe first segment 20. As shown by broken lines in FIGS. 5A to 5C, avacuum suction pipe 14 is provided at the support ring 12.

After the lamination of the prepreg 50 is completed, a caul plate 51 isattached onto the prepreg 50 as shown in FIG. 5B. Further, a baggingfilm 52 is provided so as to cover the entire prepreg 50 (and the caulplate 51), and an entire peripheral portion of the bagging film 52 issealed by a bonding member 53 (for example, a tackey tape). With this, avacuum bag is formed on the outer peripheral surface of the mold 10. Atthis time, the bagging film 52 covers not only the segment front surface21 (the outer peripheral surface of the mandrel 11) on which the prepreg50 is laminated but also a region of the segment end portion surface 22at which region the vacuum suction holes 13 are provided.

After the vacuum bag is formed, the mold 10 is accommodated in anautoclave, and the prepreg 50 is subjected to a hardening treatment at apredetermined temperature under predetermined pressure. Before the mold10 is accommodated in the autoclave, as shown in FIG. 5C, one end of aconnection hose 15 is connected to the vacuum suction hole 13 from arear surface of the first segment 20. The other end of the connectionhose 15 is connected to the vacuum suction pipe 14 provided at thesupport ring 12. With this, as shown by a block arrow Vc in FIG. 5C, theinside of the vacuum bag can be subjected to vacuum suction through thevacuum suction hole 13.

When the hardening treatment is started in the autoclave, thepredetermined pressure is applied to the vacuum bag by the autoclavefrom the outside of the mandrel 11 as shown by a block arrow Pr in FIG.5C and is heated at the predetermined temperature. As described above,since the inside of the vacuum bag is subjected to the vacuum suction,the prepreg 50 is compressed while being heated. With this, thestiffener provided on the outer peripheral surface of the mandrel 11 andthe skin formed by curing the prepreg 50 strongly stick together to beintegrated with each other. Thus, the composite material structure ismolded.

After the hardening treatment is terminated, the mold 10 is carried outof the autoclave, and the bagging film 52 and the caul plate 51 aredetached. After that, the composite material structure supported by themandrel 11 is subjected to trimming and perforation. Then, the mold 10is removed from the composite material structure. When removing the mold10, the mandrel 11 is disassembled in the reverse order to theabove-described method of assembling the mandrel 11, and the sixsegments 20 and 30 are removed from the inside of the composite materialstructure. Thus, the composite material structure is manufactured.

Seal Structure

Next, the seal structure provided between the first segment 20 and thesecond segment 30 constituting the mandrel 11 will be specificallyexplained with reference to FIGS. 6A to 7F.

The seal structure according to the present embodiment is providedbetween the adjacent segments 20 and 30. As shown in FIGS. 6A and 6B,the seal structure is constituted by at least the seal groove 25 and aseal member 26. As shown in FIGS. 7A to 7F, the seal member 26 includes:a lip portion 262 or 265 projecting outward; and a hollow portion 263therein or a concave portion 264 or 266 on an outer peripheral surfacethereof.

The seal groove 25 is provided on at least one of the adjacent segmentside surfaces 23 and 33 of the segments 20 and 30 and extends along alongitudinal direction of the segment side surface 23 or 33. In thepresent embodiment, the seal groove 25 is provided on each of thesegment side surfaces 23 of the first segment 20 and is not provided onany of the segment side surfaces 33 of the second segment 30. Asdescribed above, the segment side surface 23 of the first segment 20faces the horizontal direction or the direction inclined upward relativeto the horizontal direction. Therefore, the seal structure is providedmore easily on the segment side surface 23 of the first segment 20 thanon the segment side surface 33 of the second segment 30.

FIGS. 6A and 6B schematically show only one end portion of the firstsegment 20 as a part of the mandrel 11. Although not shown, the otherend portion of the first segment 20 has the same configuration as FIG.6A or 6B. In FIGS. 6A and 6B, since the segment side surface 23 on whichthe seal groove 25 is provided is visible from a lateral side of thefirst segment 20, the segment side surface 23 is shown as a schematicpartial side view. However, in FIGS. 6A and 6B, in order to explain thelamination of the prepreg 50 on the segment front surface 21 and theformation of the vacuum bag, the vicinity of the segment front surface21 is shown as a schematic partial sectional view as with FIGS. 5B and5C.

The seal member 26 is inserted in the seal groove 25. The seal member 26seals between the adjacent segments 20 and 30 by coupling the sidesurfaces of the segments 20 and 30 to each other. When the adjacentsegments 20 and 30 are coupled to each other, a predetermined clearanceis kept between the segment side surface 23 and the segment side surface33. With the clearance kept, the seal member 26 is crushed by beingbrought into contact with the segment side surface 23 or the segmentside surface 33. Thus, a sealed state between the segments 20 and 30 isrealized.

The seal member 26 used in the present embodiment is not formed in anannular shape but is formed in a line shape having ends. The seal member26 having such line shape can be easily produced by, for example,extrusion molding at low cost. Since the seal member 26 is disposable,i.e., is basically used once in the autoclave and thrown away, theincrease in the manufacturing cost of the composite material structurecan be avoided by avoiding the increase in the manufacturing cost of theseal member 26.

As shown in FIG. 6A, at least one seal groove 25 is only required to beformed on the segment side surface 23. However, as shown in FIG. 6B, twoseal grooves 25 that are an outer seal groove 25 a and an inner sealgroove 25 b may be formed on the segment side surface 23. Although notshown, three or more seal grooves 25 may be formed on the segment sidesurface 23. Further, when a plurality of seal grooves 25 are formed, theseal members 26 of the same type may be inserted in the seal grooves 25,or the seal members 26 of different types may be inserted in the sealgrooves 25. For example, according to the configuration shown in FIG.6B, a first seal member 26 a is inserted into the outer seal groove 25a, and a second seal member 26 b different from the first seal member 26a is inserted into the inner seal groove 25 b. It should be noted thatthe configuration of an end portion of the seal member 26 will bedescribed later.

As described above, the seal member 26 includes: the lip portion 262 or265; and at least one of the hollow portion 263 and the concave portions264 and 266. The specific configurations of the lip portions 262 and265, the hollow portion 263, and the concave portions 264 and 266 arenot especially limited. However, the seal members 26A to 26F in FIGS. 7Ato 7F are shown as typical examples.

As shown in FIG. 7A, the seal member 26A includes: the hollow portion263 in a seal main body 261 thereof; and an upright lip portion 262 onan outer peripheral surface thereof. A part of the seal main body 261 ofthe seal member 26A which part contacts a bottom surface of the sealgroove 25 when the seal member 26A is inserted in the seal groove 25 isreferred to as a seal bottom portion, and a part of the seal main body261 of the seal member 26A which part is opposed to the seal bottomportion is referred to as a seal upper portion. The upright lip portion262 is provided so as to project from the substantially flat seal upperportion in a substantially normal direction of the seal upper portion.With the seal member 26A inserted in the seal groove 25, at least a tipend of the upright lip portion 262 projects to the outside of the sealgroove 25. A cross section of the seal main body 261 of the seal member26A has a rectangular shape, and the seal bottom portion is asubstantially flat surface.

As shown in FIG. 7B, the seal member 26B includes the upright lipportion 262 as with the seal member 26A. The seal member 26B does notinclude the hollow portion 263 but includes a bottom surface concaveportion 264 at the seal bottom portion thereof. The cross section of theseal main body 261 of the seal member 26B has a substantiallytrapezoidal shape, and the width of the seal upper portion is smallerthan the width of the seal bottom portion.

As above, according to the seal members 26A and 26B, the upright lipportion 262 is included at the seal upper portion, and the hollowportion 263 is included in the seal main body 261, or the bottom surfaceconcave portion 264 is included at the seal bottom portion. Each of thehollow portion 263 and the bottom surface concave portion 264 serves asa thinned part in the seal main body 261. Therefore, when the adjacentsegment side surfaces 23 and 33 of the segments 20 and 30 are coupled toeach other, each of the hollow portion 263 and the bottom surfaceconcave portion 264 is easily crushed by being pressed by the segmentside surface 33 of the second segment 30.

The upright lip portion 262 projects outward (in a direction toward thesecond segment 30) from the segment side surface 23 of the first segment20 and has elasticity derived from the material of the seal member 26Aor 26B. Therefore, the upright lip portion 262 tries to stand in a stateof being coupled to the segment side surface 33. With this, the insideof the seal groove 25 is satisfactorily sealed by the seal main body 261and the upright lip portion 262.

At this time, when viewing the seal members 26A and 26B from above, thehollow portion 263 or the bottom surface concave portion 264 is locatedsubstantially immediately under the upright lip portion 262, so that thehollow portion 263 or the bottom surface concave portion 264 which iseasily crushed and the upright lip portion 262 which is biased in thestanding direction by the elasticity are located on the substantiallysame straight line. Therefore, when assembling the mandrel 11, the sealmembers 26A and 26B can be compressed without applying a high load, anda satisfactory sealed state can be realized between the adjacentsegments 20 and 30. As a result, the segments 20 and 30 can be moved bya low load while securing the satisfactory sealed state, and therefore,the positions of the outer peripheral surfaces of the adjacent segments20 and 30 can be easily adjusted.

According to the seal member 26A shown in FIG. 7A and the seal member26B shown in FIG. 7B, the upright lip portion 262 in a substantiallyupright state is included, and the hollow portion 263 or the bottomsurface concave portion 264 as a deformation structure by which the sealmain body 261 is crushed in a cross sectional direction is located alongthe upright lip portion 262 on the substantially same straight line asthe upright lip portion 262. However, the seal member 26 according tothe present embodiment is not limited to this configuration. Forexample, as shown in FIGS. 7C to 7F, an inclined lip portion 265 may beincluded instead of the upright lip portion 262.

For example, as shown in FIG. 7C, the seal member 26C includes theinclined lip portion 265 at the seal upper portion thereof. The inclinedlip portion 265 projects so as to be inclined relative to the normaldirection of the seal upper portion. A direction connecting the sealbottom portion and the seal upper portion in the cross section of theseal main body 261 is referred to as a “vertical direction of the crosssection of the seal member 26,” and a direction perpendicular to thevertical direction is referred to as a “lateral direction of the crosssection of the seal member 26.” Unlike the seal members 26A and 26B, thecross section of the seal main body 261 of the seal member 26C has a“laterally long” shape, not a “vertically long” shape that extends overthe entire cross section of the seal groove 25.

Therefore, in the seal member 26C, a movable space in which the inclinedlip portion 265 is movable in an upper-lower direction is formed betweenthe inclined lip portion 265 and the seal main body 261. As with theseal member 26B, the bottom surface concave portion 264 is formed at theseal bottom portion of the seal member 26C. In addition, the movablespace can also be regarded as a concave portion provided on the outerperipheral surface of the seal member 26C.

As shown in FIG. 7D, as with the seal member 26C, the seal member 26Dincludes the inclined lip portion 265, and the cross section of the sealmain body 261 has a “laterally long” shape. However, the seal member 26Dincludes the hollow portion 263 instead of the bottom surface concaveportion 264.

As above, according to the seal members 26C and 26D, the inclined lipportion 265 is included at the seal upper portion, and the bottomsurface concave portion 264 is included at the seal bottom portion ofthe seal main body 261 having a “laterally long” cross section, or thehollow portion 263 is included in the seal main body 261. When theadjacent segment side surfaces 23 and 33 of the segments 20 and 30 arecoupled to each other, the inclined lip portion 265 is easily presseddownward by the existence of the movable space immediately under theinclined lip portion 265, but the inclined lip portion 265 tries tostand by its elasticity in a state of contacting the segment sidesurface 33. Further, according to the seal main body 261 that is“laterally long,” the bottom surface concave portion 264 or the hollowportion 263 is crushed in accordance with the pressing of the inclinedlip portion 265. With this, the inside of the seal groove 25 issatisfactorily sealed by the seal main body 261 and the inclined lipportion 265.

Further, the seal member 26 according to the present embodiment mayinclude the inclined lip portion 265, and the width of the seal upperportion may be larger than the width of the seal bottom portion.

For example, as shown in FIG. 7E, the seal member 26E includes theinclined lip portion 265, and the bottom surface concave portion 264 isformed at the seal bottom portion. In addition, the width of the sealupper portion is larger than the width of the seal bottom portion, andan upper surface concave portion 266 is formed at a position of the sealupper portion which position is adjacent to the inclined lip portion265.

Further, as shown in FIG. 7F, the seal member 26F includes the inclinedlip portion 265, and the bottom surface concave portion 264 is formed atthe seal bottom portion. In addition, the width of the seal upperportion is larger than the width of the seal bottom portion, and thehollow portion 263 is formed in the seal main body 261.

As above, according to the seal members 26E and 26F, the inclined lipportion 265 is included at the seal upper portion larger in width thanthe seal bottom portion, and the bottom surface concave portion 264 isincluded at the seal bottom portion, or the hollow portion 263 isincluded in the seal main body 261. When the adjacent segment sidesurfaces 23 and 33 of the segments 20 and 30 are coupled to each other,the inclined lip portion 265 is easily pressed downward by the existenceof the movable space immediately under the inclined lip portion 265, butthe inclined lip portion 265 tries to stand by its elasticity in a stateof contacting the segment side surface 33. Further, according to theseal main body 261, the bottom surface concave portion 264 or the hollowportion 263 is crushed in accordance with the pressing of the inclinedlip portion 265. In addition, since the seal upper portion is wide, theseal groove 25 can be satisfactorily sealed in a width directionthereof.

Especially, when the upper surface concave portion 266 is formed inaddition to the movable space as in the seal member 26E, or when thehollow portion 263 is formed in addition to the movable space as in theseal member 26F, an edge portion of the wide seal upper portion easilymoves toward an inner side of the seal main body 261 by the deformationof the upper surface concave portion 266 or the hollow portion 263.Therefore, the sealed state in the lateral direction of the crosssection can be improved by the wide seal upper portion. With this, theinside of the seal groove 25 is satisfactorily sealed by the seal mainbody 261, the inclined lip portion 265, and the wide seal upper portion.

The selection from the seal members 26A to 26F shown in FIGS. 7A to 7Fis not especially limited. The seal member 26 having a preferredcross-sectional shape can be selected depending on various conditions,such as the degree of the seal performance required for the sealstructure, the material of the seal member 26, and moving loads of thesegments 20 and 30. Further, as described below, when a plurality ofseal grooves 25 are formed on the segment side surface 23, the sealmembers 26 having different cross sections can be selected depending onconditions required for the respective seal grooves 25.

For example, according to the configuration shown in FIG. 6B, one of theseal members 26C to 26F each including the inclined lip portion 265 canbe used as the first seal member 26 a inserted in the outer seal groove25 a, and the seal member 26A or 26B including the upright lip portion262 can be used as the second seal member 26 b inserted in the innerseal groove 25 b.

High pressure is applied from the outside of the seal groove 25 by theautoclave. Therefore, any one of the seal members 26C to 26F is arrangedin the outer seal groove 25 a such that the pressure is applied to themovable region located immediately under the inclined lip portion 265.With this, the inclined lip portion 265 can be strongly biased towardthe standing side by not only the elasticity derived from the materialbut also the pressure difference. Thus, the further satisfactory sealedstate can be realized.

The inside of the seal groove 25 faces the inside of the vacuum bag. Inthermal curing by the autoclave, the matrix resin (thermosetting resin)constituting the prepreg 50 is once softened before being cured. At thistime, there is a possibility that the softened matrix resin flows towardthe seal groove 25. Therefore, it is preferable that the leak of thematrix resin be effectively prevented or suppressed.

To be specific, the second seal member 26 b inserted in the inner sealgroove 25 b is required to have performance (pressure seal performance)of redundantly sealing high pressure outside the vacuum bag, togetherwith the first seal member 26 a inserted in the outer seal groove 25 a.In addition, the second seal member 26 b inserted in the inner sealgroove 25 b is required to have performance (matrix resin sealperformance) of preventing the leak of the softened matrix resin in thevacuum bag. Therefore, the seal member 26A or 26B including the uprightlip portion 262 is arranged in the inner seal groove 25 b.

According to the seal member 26, the high pressure outside the vacuumbag can be satisfactorily sealed (the satisfactory pressure sealperformance can be realized) by the crushed upright lip portion 262. Inaddition, since the movable region and the upper surface concave portion266 are not provided around the upright lip portion 262, the upright lipportion 262 does not incline unlike the inclined lip portion 265.Therefore, the softened matrix resin generated in the vacuum bag can besatisfactorily stopped (the satisfactory matrix resin seal performancecan be realized) by the upright lip portion 262. In addition, since theupper surface concave portion 266 and the like are not included asdescribed above, the matrix resin can be prevented from staying in aconcave portion at an outer periphery of the seal member 26.

Configuration of End Portion of Seal Member

Next, a preferred configuration of the end portion of the seal member 26in the seal structure configured as above will be specifically explainedwith reference to FIGS. 6A, 6B, and 8A to 9D.

In the seal structure according to the present embodiment, the sealmember 26 inserted in the seal groove 25 is formed in a line shapehaving ends, not an annular shape. As described above, regarding thecross sectional direction of the seal member 26, by the lip portions 262and 265, the hollow portion 263, and the concave portions 264 and 266(see FIGS. 7A to 7F), the sealed state can be formed by compressing theseal member 26 without applying a high load. On the other hand,regarding the longitudinal direction of the seal member 26, theexpansion (linear expansion) generated in the longitudinal direction bythe heating during the autoclaving can be easily adjusted by both endportions of the seal member 26.

Specifically, for example, as shown in FIGS. 6A and 6B, the linearexpansion of the seal member 26 can be adjusted only by pressing a sealend portion pressing member 27 against the end portion of the sealmember 26 such that the end portion is not exposed. The seal groove 25may have a line shape including an end portion that reaches the segmentend surface 24. However, as shown in FIGS. 6A and 6B, it is preferablethat the end portion of the seal groove 25 be bent toward the segmentend portion surface 22. With this, an opening of the end portion of theseal groove 25 is exposed on the segment end portion surface 22 of thefirst segment 20, and therefore, the seal end portion pressing member 27can be provided on the segment end portion surface 22.

The segment end surface 24 of the first segment 20 is fixed to thesupport ring 12 through the fixing member 16. Therefore, if the seal endportion pressing member 27 is provided on the segment end surface 24,this may influence the movement of the first segment 20 during theassembling of the mandrel 11 or the fixing of the first segment 20 tothe support ring 12. However, since the seal end portion pressing member27 is provided on the segment end portion surface 22, such influences onthe assembling of the mandrel 11 can be avoided.

Further, as shown in FIGS. 6A and 6B, an edge portion of the baggingfilm 52 constituting the vacuum bag reaches the segment end portionsurface 22. When the end portion of the seal member 26 reaches thesegment end portion surface 22, the bagging film 52 also covers an upperside of the end portion of the seal member 26, and the seal end portionpressing member 27 can press the end portion of the seal member 26 fromabove.

The specific configuration of the seal end portion pressing member 27 isnot especially limited. As shown in FIGS. 6A, 6B, and 8B, the seal endportion pressing member 27 is only required to be a plate-shaped memberhaving rigidity and be fixed to the segment end portion surface 22 ofthe first segment 20 by a known fastening member 28 (for example, abolt). When the seal end portion pressing member 27 has rigidity, theseal end portion pressing member 27 can be pressed against the endportion of the seal member 26 by fixing only one of both end portions ofthe seal end portion pressing member 27 with the fastening member 28such that the end portion of the seal member 26 is not exposed. Withthis, as shown in FIGS. 6A, 6B, and 8A, a fastening member insertionhole 29 (shown only in FIG. 8A) can be provided at a position closer tothe segment end surface 24 than the seal groove 25. Therefore, forexample, an opening portion for the fastening member 28 does not have tobe formed on the bagging film 52, and therefore, the degree of vacuum ofthe vacuum bag can be prevented from deteriorating.

As described above, the cross section of the seal member 26 includes thelip portion 262 or 265, the hollow portion 263, the concave portion 264or 266, and the like (see FIGS. 7A to 7F). Therefore, even when the sealmember 26 is inserted in the seal groove 25, a gap is necessarily formedbetween the opening of the end portion of the seal groove 25 exposed onthe segment end portion surface 22 and the end portion of the sealmember 26. On this account, as shown in FIGS. 6A and 6B, the opening ofthe end portion of the seal groove 25 and the end portion of the sealmember 26 are only required to be covered with a bonding member 54 (forexample, a tackey tape) and then pressed by the seal end portionpressing member 27.

Especially when a plurality of seal grooves 25 are provided, and aplurality of seal members 26 are used, the end portions of the sealmembers 26 are covered with the bonding member 54, and with this, theend portions of the seal members 26 are connected to one another, andtherefore, the seal members 26 can be formed as a single seal member.Thus, the more satisfactory and stable sealed state can be realizedbetween the adjacent segments 20 and 30.

As described above, the bonding member 53 seals the entire peripheralportion of the bagging film 52. The bonding member 53 needs to beconnected to the bonding member 54 covering the end portion of the sealmember 26. With this, the vacuum bag sealed by the bonding members 53and 54 and the seal member 26 is formed. In the schematic sections shownin FIGS. 6A and 6B, only the bonding member 54 is shown. However, inorder to indicate that the bonding member 53 is connected to the bondingmember 54, the reference sign 53 with parentheses is also shown.

Next, one example of the adjustment of the end portions of the sealmembers 26 by the seal end portion pressing member 27 will be explainedby using an example in which as shown in FIGS. 6B, 8A, and 8B, the outerseal groove 25 a and the inner seal groove 25 b are provided as the sealgrooves 25, and the first seal member 26 a and the second seal member 26b are used as the seal members 26.

First, as schematically shown in FIG. 9A, the first seal member 26 a isinserted in the outer seal groove 25 a formed on the segment sidesurface 23 of the first segment 20, and the second seal member 26 b isinserted in the inner seal groove 25 b formed on the segment sidesurface 23 of the first segment 20. Both end portions of the first sealmember 26 a and both end portions of the second seal member 26 b areexposed from the openings of the end portions of the outer seal groove25 a and the openings of the end portions of the inner seal groove 25 bon the segment end portion surface 22. It should be noted that theprepreg 50 is laminated on the segment front surface 21, and the caulplate 51 is placed on the prepreg 50.

Next, as shown in FIG. 9B, each of both end portions of the first sealmember 26 a exposed from the openings of the end portions of the outerseal groove 25 a and both end portions of the second seal member 26 bexposed from the openings of the end portions of the inner seal groove25 b is cut so as to have a length of about several millimeters from thesegment end portion surface 22. Then, as shown in FIG. 9C, each of thebonding members 54 cover the opening of the end portion of the outerseal groove 25 a and the opening of the end portion of the inner sealgroove 25 b so as to connect the end portion of the first seal member 26a and the end portion of the second seal member 26 b to each other. Withthis, the first seal member 26 a and the second seal member 26 b can beregarded as a single seal member. The single seal member has an annularstructure in appearance.

After that, as shown in FIG. 9D, the bagging film 52 covers the segmentfront surface 21 of the first segment 20 (i.e., covers the prepreg 50formed on the outer peripheral surface of the mandrel 11 and the caulplate 51 placed on the prepreg 50), and the seal end portion pressingmembers 27 are attached onto the bagging film 52. With this, the sealend portion pressing member 27 presses, from above the bagging film 52,the bonding member 54 by which the end portion of the first seal member26 a and the end portion of the second seal member 26 b are connected toeach other. Therefore, the end portions of the first seal member 26 aand the second seal member 26 b can be effectively prevented from beingexposed from the segment end portion surface 22 even during theautoclaving.

The bonding member 53 for bonding the peripheral portion of the baggingfilm 52 and the fastening member 28 (see FIG. 6B) for fixing the sealend portion pressing member 27 are not shown in FIG. 9D for convenienceof explanation. The bonding member 54 covering the openings of the endportions of the seal grooves 25 is not limited to the configurationsshown in FIGS. 9C and 9D. Without connecting the end portion of thefirst seal member 26 a and the end portion of the second seal member 26b as schematically shown in FIG. 6B, only the opening of the end portionof the outer seal groove 25 a may be covered with one bonding member 54,and only the opening of the end portion of the inner seal groove 25 bmay be covered with another bonding member 54.

MODIFIED EXAMPLE

The mold to which the seal structure according to the present disclosureis applied is not limited to the mold 10 (see FIGS. 1A to 4) includingthe mandrel 11 constituted by the six segments 20 and 30 as described inthe present embodiment. The mold according to the present disclosure isonly required to be located inside a hollow composite materialstructure, be constituted by a plurality of segments, and be kept as asingle structure by coupling adjacent side surfaces of the segments toeach other.

The specific shape of the mold is not limited to the above-describedcylindrical shape (a hollow shape with a substantially constant overalldiameter) and may be a conical tubular shape (a hollow shape thatdecreases in diameter from one end to the other) or a truncated conetubular shape (a hollow shape in which diameters of both ends aredifferent from each other, and an intermediate diameter graduallychanges). The seal structure according to the present disclosure is onlyrequired to be provided at the adjacent side surfaces of the segmentsconstituting the mold configured as above. Further, the shape of eachsegment is not limited to the rectangular flat plate shape, and variousshapes may be adopted as long as the segments can constitute the mandrel11 as a single structure.

Further, in the present embodiment, the mandrel 11 is constituted by thethree first segments 20 and the three second segments 30 (see FIG. 1B).However, the configuration of the mandrel 11 is not limited to this. Forexample, the number of segments may be five or less or may be seven ormore. The types of the segments are not limited to two types that arethe first segment 20 and the second segment 30. A segment different intype from the segments 20 and 30 may be included, or two or more typesof segments different in type from the segments 20 and 30 may be used.Or, the mandrel 11 may be constituted by segments of only one type.

In the present embodiment, the seal groove is provided at the firstsegment 20 including the segment side surfaces 23 facing the horizontaldirection or the direction inclined upward relative to the horizontaldirection. However, the configuration of the seal groove is not limitedto this. The seal groove may be provided on the segment side surface 33of the second segment 30, or the segment grooves may be provided on boththe segment side surface 23 and the segment side surface 33. To bespecific, in the present embodiment, some of the segments have the sealgrooves on the side surfaces, and the other segments do not have theseal grooves. However, all the segments may have the seal grooves.

In the present embodiment, the seal grooves are provided only at thefirst segments 20. However, the configuration of the seal grooves is notlimited to this. To be specific, the seal groove may be provided on onlyone of the adjacent side surfaces of the segments, or the sealstructures may be provided on both of the adjacent side surfaces of thesegments. Examples of a case where the seal grooves are provided at allthe segments include a configuration in which the seal groove isprovided on only one of both side surfaces of each segment and aconfiguration in which the seal grooves are provided on both sidesurfaces of each segment. When the seal groove is provided on only oneof both side surfaces of each segment, this corresponds to theconfiguration in which the seal groove is provided on only one of theadjacent side surfaces of the segments. When the seal grooves areprovided on both side surfaces of each segment, this corresponds to theconfiguration in which the seal grooves are provided on both of theadjacent side surfaces of the segments.

When the seal grooves are provided at both of the adjacent segments, itis preferable that the seal grooves be displaced from each other. Oneexample may be a configuration in which: the outer seal groove and thefirst seal member are provided on one of the adjacent side surfaces ofthe segments; and the inner seal groove and the second seal member areprovided on the other side surface. Further, in the present embodiment,the number of seal grooves formed on the side surface of the segment isone (see FIG. 6A) or two (see FIG. 6B), and the number of seal memberseach inserted in the seal groove is one or two. However, the number ofseal grooves and the number of seal members are not limited to these.The number of seal grooves may be three or more, and the number of sealmembers may be three or more. It should be noted that when a pluralityof seal grooves are provided on the side surface of the segment, acomponent (for example, a vacuum suction hole) for performing the vacuumsuction between the seal grooves may be additionally provided.

The specific configuration of the seal member inserted in the sealgroove is not especially limited. As described above, the seal member isonly required to: include the lip portion; and be hollow therein orinclude the concave portion on the outer peripheral surface thereof. Thespecific shape of the lip portion is not especially limited. The lipportion may be the upright lip portion 262, the inclined lip portion265, or a lip portion having a different shape and is only required tohave such a shape as to extend at the seal upper portion along thelongitudinal direction of the seal main body 261.

The concave portion is only required to be formed on at least the sealbottom portion. However, as described above, the concave portion may beformed on the seal upper portion so as to be located near the lipportion, or although not shown, the concave portion may be formed on theside surface of the seal main body. Basically, the hollow portion formedin the seal main body is only required to have a substantially circularsection. However, the hollow portion may have an oval section or apolygonal section. As with the lip portion, each of the hollow portionand the concave portion is only required to have such a shape as toextend along the longitudinal direction of the seal main body 261 in theseal main body or on the outer peripheral surface of the seal main body.

The width of the cross section of the seal member is not especiallylimited. The seal upper portion and the seal bottom portion may besubstantially the same in width as each other (see FIGS. 7A, 7C, and7D). The seal upper portion may be smaller in width than the seal bottomportion (see FIG. 7B). The seal upper portion may be larger in widththan the seal bottom portion (see FIGS. 7E and 7F). A wide portion maybe formed between the seal upper portion and the seal bottom portion(the side surface of the seal main body). The width of the seal membermay be reduced by the formation of the above-described concave portion.A protruding portion may be formed on the side surface of the seal mainbody.

As above, a seal structure of a mold for manufacturing a compositematerial structure according to the present disclosure includes: sealgrooves each provided on at least one of adjacent side surfaces ofsegments; and seal members each formed in a line shape having ends andinserted in the seal groove to seal between the segments by coupling theadjacent side surfaces of the segments to each other. A part of the sealmember which part contacts a bottom surface of the seal groove when theseal member is inserted in the seal groove is referred to as a sealbottom portion. A part of the seal member which part is opposed to theseal bottom portion is referred to as a seal upper portion. A lipportion is provided at the seal upper portion such that at least a tipend of the lip portion projects to an outside of the seal groove whenthe seal member is inserted in the seal groove. The seal member ishollow therein or includes a concave portion on at least the seal bottomportion of the seal member. When the adjacent side surfaces of thesegments are coupled to each other, the seal member is crushed in across sectional direction by the other of the adjacent side surfaces ofthe segments.

According to this configuration, the seal member includes the lipportion and the hollow or concave portion and is formed in a lineconfiguration having ends. Therefore, regarding the cross sectionaldirection of the seal member, the sealed state can be formed bycompressing the seal member without applying a high load. Regarding thelongitudinal direction of the seal member, the expansion (linearexpansion) in the longitudinal direction generated by the heating duringthe autoclaving can be easily adjusted by both end portions of the sealmember. With this, the more satisfactory and stable sealed state can berealized between the adjacent segments. In addition, since the increasein the moving load of the segment can be suppressed or avoided, thelevel difference between the adjacent segments can be satisfactorilyadjusted when assembling the mold. As a result, the complication of themanufacture of the composite material structure can be suppressed oravoided while realizing the satisfactory sealed state between theadjacent segments.

In the seal structure configured as above, the lip portion may projectso as to be inclined relative to a normal direction of the seal upperportion.

In the seal structure configured as above, the concave portion may alsobe formed on the seal upper portion so as to be located close to the lipportion.

In the seal structure configured as above, a width of the seal upperportion in a cross section of the seal member may be larger than a widthof the seal bottom portion.

In the seal structure configured as above, the lip portion may projectin a normal direction of the seal upper portion, and a width of the sealupper portion in a cross section of the seal member may be smaller thana width of the seal bottom portion.

In the seal structure configured as above, a surface of the segmentwhich surface constitutes an outer peripheral surface of the singlestructure may be referred to as a front surface of the segment. Both endportions of the seal groove may be bent toward the front surface of thesegment. When the seal member is inserted in the seal groove, both endportions of the seal member may be pressed by respective end portionpressing members, provided on the front surface of the segment, so asnot to be exposed from the front surface of the segment.

In the seal structure configured as above, the plurality of segments mayinclude: a segment having the side surface on which the seal groove isprovided; and a segment having the side surface on which the seal grooveis not provided.

In the seal structure configured as above, a surface of the segmentwhich surface constitutes an outer peripheral surface of the singlestructure may be referred to as a front surface of the segment. Thesegments may include two types of segments that are first segments eachhaving such a shape that when the first segment is arranged horizontallywith the front surface facing upward, each of both side surfaces of thefirst segment faces a horizontal direction or a direction inclinedupward relative to the horizontal direction, and second segments eachhaving such a shape that when the second segment is arrangedhorizontally with the front surface facing upward, each of both sidesurfaces of the second segment faces a direction inclined downwardrelative to the horizontal direction. The first segments and the secondsegments may be kept as the single structure by alternately arrangingthe first and second segments and coupling the side surfaces of thefirst and second segments to each other. The seal grooves may beprovided only on the side surfaces of the first segments.

The present invention is not limited to the above embodiment, andvarious modifications may be made within the scope of the claims. Anembodiment obtained by suitably combining technical means disclosed indifferent embodiments and a plurality of modified examples is alsoincluded in the technical scope of the present invention.

From the foregoing explanation, many modifications and other embodimentsof the present invention are obvious to one skilled in the art.Therefore, the foregoing explanation should be interpreted only as anexample and is provided for the purpose of teaching the best mode forcarrying out the present invention to one skilled in the art. Thestructures and/or functional details may be substantially modifiedwithin the scope of the present invention.

INDUSTRIAL APPLICABILITY

The present invention is widely used in the fields of molding a largeand substantially cylindrical composite material structure, such as afuselage of an aircraft.

REFERENCE SIGNS LIST

-   -   10 mold for manufacturing composite material structure (mold)    -   11 mandrel (single structure)    -   12 support ring    -   20 first segment (segment)    -   21 segment front surface    -   22 segment end portion surface    -   23 segment side surface    -   24 segment end surface    -   25 seal groove    -   25 a outer seal groove (seal groove)    -   25 b inner seal groove (seal groove)    -   26 seal member    -   26 a first seal member (seal member)    -   26 b second seal member (seal member)    -   27 seal end portion pressing member (end portion pressing        member)    -   30 second segment (segment)    -   33 segment side surface    -   50 prepreg    -   261 seal main body    -   262 upright lip portion (lip portion)    -   263 hollow portion (inner hollow)    -   264 bottom surface concave portion (concave portion)    -   265 inclined lip portion (lip portion)    -   266 upper surface concave portion (concave portion)

The invention claimed is:
 1. A seal structure of a mold formanufacturing a hollow composite material structure, the mold beinglocated in the hollow composite material structure, being constituted bya plurality of segments, and being kept as a single structure bycoupling adjacent side surfaces of the segments to each other, the sealstructure being provided at the adjacent side surfaces of the segments,the seal structure comprising: seal grooves each provided on at leastone of the adjacent side surfaces of the segments, the seal groovesincluding a first seal groove that is provided on an adjacent sidesurface of a first segment; and seal members each formed in a line shapehaving ends and inserted in a respective seal groove to seal between thesegments by coupling the adjacent side surfaces of the segments to eachother, wherein: the seal members include a first seal member that isinserted in the first seal groove, the first seal member including: aseal bottom portion that contacts a bottom surface of the first sealgroove; a seal upper portion that is opposed to the seal bottom portion;and a lip portion provided at the seal upper portion such that at leasta tip end of the lip portion projects to an outside of the first sealgroove; the first seal member is hollow therein or includes a concaveportion on at least the seal bottom portion of the first seal member;the adjacent side surface of the first segment and an adjacent sidesurface of an adjacent second segment are configured to be coupled toeach other such that the first seal member is crushed in a crosssectional direction by the adjacent side surface of the second segment;both end portions of the first seal groove are bent toward a frontsurface of the first segment, the front surface being an outerperipheral surface of the single structure; and the first seal member isinserted into the first seal groove such that both ends of the firstseal member are pressed by respective end pressing members provided onthe front surface of the first segment so as to not be exposed from thefront surface of the first segment.
 2. The seal structure according toclaim 1, wherein the lip portion projects so as to be inclined relativeto a normal direction of the seal upper portion.
 3. The seal structureaccording to claim 2, wherein the first seal member includes the concaveportion on at least the seal bottom portion, and a second concaveportion is formed on the seal upper portion so as to be located close tothe lip portion.
 4. The seal structure according to claim 2, wherein awidth of the seal upper portion in a cross section of the first sealmember is larger than a width of the seal bottom portion.
 5. The sealstructure according to claim 1, wherein: the lip portion projects in anormal direction of the seal upper portion; and a width of the sealupper portion in a cross section of the first seal member is smallerthan a width of the seal bottom portion.
 6. The seal structure accordingto claim 1, wherein the adjacent side surface of the second segment doesnot have a seal groove.
 7. The seal structure according to claim 6,wherein: the first segment has a shape such that when the first segmentis arranged horizontally with the front surface facing upward, each ofboth side surfaces of the first segment faces a horizontal direction ora direction inclined upward relative to the horizontal direction, thesecond segment has a shape such that when the second segment is arrangedhorizontally with the front surface facing upward, each of both sidesurfaces of the second segment faces a direction inclined downwardrelative to the horizontal direction; the plurality of segments includesa plurality of first segments and second segments, and the singlestructure is formed by alternately arranging the first and secondsegments and coupling side surfaces of the first and second segments toeach other; and the seal grooves are provided only on the side surfacesof the first segments.